A Taylor dispersion method is used to measure ternary multicomponent diffusion coefficients of three-component liquid systems. Ternary mutual diffusion coefficients measured by this method (D(11), D(22), D(12), and D(21)) are reported for aqueous solutions of P-cyclodextrin (beta-CD) + caffeine at 298.15 K at carrier concentrations from (0.000 to 0.010) mol center dot dm(-3), for each solute, respectively. These diffusion coefficients have been measured having in mind a better understanding of the structure of these systems and the thermodynamic behavior of caffeine and cyclodextrin in solution.